[Bug]: react/no-unused-prop-types returns no errors when using the spread operator in JSX element

[david-martyn-ford]

Is there an existing issue for this?

• I have searched the existing issues and my issue is unique
• My issue appears in the command-line and not only in the text editor

Description Overview

When using the spread operator within a JSX component, the rule react/no-unused-prop-types no longer detects any errors.

Demo Code

package.json

{
  "scripts": {
    "lint": "eslint Demo.tsx"
  },
  "private": true,
  "devDependencies": {
    "@types/react": "^18.2.0",
    "@typescript-eslint/parser": "^5.59.1",
    "eslint": "^8.39.0",
    "eslint-plugin-react": "^7.32.2",
    "typescript": "^5.0.4"
  },
  "dependencies": {
    "react": "^18.2.0"
  }
}

.eslintrc.js

module.exports = {
  parser: "@typescript-eslint/parser",
  extends: ["plugin:react/recommended"],
  parserOptions: {
    ecmaVersion: 2018,
    sourceType: "module",
    ecmaFeatures: {
      jsx: true
    }
  },
  settings: {
    react: {
      version: "detect"
    }
  },
  rules: {
    "react/no-unused-prop-types": 2
  }
};

Demo.tsx

import React from "react";

type Props = {
  foo: string;
  bar: string; // <-- unused prop
};

const Demo: React.FC<Props> = ({ foo }) => {
  return <div {...{}}>{foo}</div>;
};

export default Demo;

What is happening?

With spread operator

No error is detected when a prop type is unused within the component a spread operator is used in an element for attributes.

Without spread operator

When removing the spread operator, the unused prop is detected

Steps to reproduce

yarn lint

Expected Behavior

bar should be marked as a linting error

eslint-plugin-react version

v7.32.2

eslint version

v8.39.0

node version

v18.11.0

[ljharb]

When you're spreading the props object, the rule intentionally stops warning on things, because if you're doing this (don't) you've basically given up on anyone, human or linter, from being able to figure out what's in that object by reading the code.

This specific case is weird because you're not spreading the props object, so I wouldn't expect this to affect anything.